North of the Imperial City, there is a road called "The Red Ring Road" on your map. Head to where the tail of the "G" is in "Ring" on the map to find a farm called "Aleswell". Use a detect life item or spell to see that the seemingly empty small pasture actually has some invisible sheep. If you do not have any life detect items, just look closely to see that there actually are sheep. If you kill them they become visible again.